Screen stencil frame



Dec. 27, 1932. FLOCKHART 1,892,268

SCREEN STENC IL FRAME Original Filed Dec. 13, 1950 a' iii W ml INVENTOR: JAMES. FLOCKHART.

ATTORNEY.

Patented Dec. 27, 1932 J'AliIES FLOCKHART, OF SAN FRANCISCO, CALIFORNIA scnnnn srnncn; FRAME Application filed December 13, 1930, Serial No. 502,114. Renewed May 24-, 1932.

This invention relates to screen stencil frames and more particularly to the manner of stretching the screens.

For further particulars reference is made to my copending application Serial Number 438,504, filed March 24, 1930, entitled Stencil printing apparatus.

The principal object of the invention is to provide means for stretching silk cloth stencil screens taut, without wrinkling.

Another object is to remove distortion from the stencil in the first and subsequent stretchings.

A further object is to so construct and arrange the frame that the stencil screen may be removed for filing and replaced for use as occasion requires, without injury to the screen and with the assurance of accurate registration and freedom from distortion.

Other objects and advantages will appear as the description progresses.

In this specification and the accompanying drawing the invention is disclosed in its preferred form. But it is to be understood that it is not limited to this form because it may be embodied in other forms. It is also to be understood that in and by the claims following the description itis desired to cover the invention in whatsoever form it may be embodied.

In the one sheet of drawing:

Fig. 1 is a fragmentary plan view from above of a screen stencil frame built in accordance with this invention.

' Fig. 2 is a fragmentary detail in perspective of the corner structure of the frame.

Fig. 3 is a cross-section of the side rails of the frame.

In detail the construction illustrated in the drawing comprises the rectangular open rigid integral base frame, see Fig. 1. The side rails 1-1 of this frame have the smooth bottom surface 2, and the inner vertical side 3, see Fig. 3. The bottom surface 2 of each rail is narrower than the top 1, and has the rounded edge at 4:. The lateral side rails of the frame are longitudinally grooved as at 5. The edges of these grooves are rounded as at 67. The rails 1 are horizontally drilled and tapped to receive the cap screws 8.

The outer clamp bars 99 are arranged around the base frame to which they are clamped by the cap screws 8. These bars 9 are also grooved at 11in registry with the grooves 5 in the base frame.

The adjusting screws 1212 are threaded in the bars 9 and project into the grooves 11 at intervals. The semi-flexible tension rods 13 are confined within the combined grooves 511 and rest against the ends of the screws 12.

The stencil screen 14 consists of a piece of silk bolting cloth or other conventional material suitable for the purpose. The four corners of the material are cut away at the margin of the stencil field. The lateral mar: gins 15, extending beyond the sides of the base frame, are folded upward around the corners 1 and are clamped between the outer sides of the base frame and the inner sides of the bars 9, by the screws 8. The screws 1212 are then progressively set up to force the rods 13 against the marginal tabs 15 which draws the screen stencil area 14 taut.

After the screen area has been thus st etched free of wrinkles and puckers throughout its whole area, it is processed to form the stencil in the conventional manner.

It has been common practice when a stencil is preserved for future impressions, to store away the complete assembly, including the frame and stencil. It is one of the major advantages of this invention that the screen can be removed and filed away in the mini-' mum of space. This saves bulk in preserving the stencil and avoids tying up capital in duplicated expensive frames.

This economy is made possible by the ad- 7 justable feature of the screws and rods' 1213. The screen take-up in the grooves 5-11, previously descrlbed, makes it possible to remcunt a screen and not only take up the puckers and wrinkles, but to also rectify any dstortlon of the stenc1l image by dis- It has the p can be alined in multicolor impressions, wherein several different color screens are re quired to complete one image.

Having thus described this invention, What I claim and desire to secure by Letters Patent is:

1. A stencil frame including a base frame having a groove therein; means for clamping the margin of a screen on said frame and means for forcing said screen adjacent said margin into said goove;

2. A stencil frame including a base frame having a lateral groove therein; clamping bars attached to said frame and engaging the margin of a stencil screen; tension rods in said groove engaging said screen adjacent saidmargin and means for moving said rods.

3. A stencil frame including a base frame having a lateral groove in the sides thereof; clamping bars attached to the sides of said frame, over said groove; tension rods in said groove; and adjusting, means in said bars, engaging said rods.

4. A stencil frame including abase frame having alateral groove in the sides thereof; clamping bars attached to the sides of said frame andhaving grooves therein registering with the grooves invsaid frame; rods in said grooves; and adjusting means in said bars engaging said rods.

5. A stencil frame including a base frame having a lateral groove in the sides thereof; clamping bars screwed to the sides of said frame and having grooves therein registering with the grooves in said frame; rods in said grooves; and screws-threaded in said bars and engaging said rods.

In testimony whereof I have hereunto set my handthis 5th day of December, 1980.

JAMES FLOGKHART. 

